| Date | Wed, 16 Dec 2009 19:56:47 -0800 | From | Greg KH <> | Subject | [110/151] b44 WOL setup: one-bit-off stack corruption kernel panic fix |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Stanislav Brabec <sbrabec@suse.cz>
[ Upstream commit: e0188829cb724e7d12a2d4e343b368ff1d6e1471 ]
About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic with kernels compiled with stack-protector.
Checking b44_magic_pattern() return values, one call of b44_magic_pattern() returns 127. It means, that set_bit(128, pmask) was called on line 1509. It means that bit 0 of 17th byte of pmask was overwritten. But pmask has only 16 bytes. Stack corruption happens.
It seems that set_bit() on line 1509 always writes one bit off.
The fix does not only solve the stack corruption, but also makes Wake On LAN working on my onboard B44 on Asus A7V-333X mainboard.
It seems that this problem affects all kernel versions since commit 725ad800 ([PATCH] b44: add wol for old nic) on 2006-06-20.
Signed-off-by: Stanislav Brabec <sbrabec@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- drivers/net/b44.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/net/b44.c +++ b/drivers/net/b44.c @@ -1505,8 +1505,7 @@ static int b44_magic_pattern(u8 *macaddr for (k = 0; k< ethaddr_bytes; k++) { ppattern[offset + magicsync + (j * ETH_ALEN) + k] = macaddr[k]; - len++; - set_bit(len, (unsigned long *) pmask); + set_bit(len++, (unsigned long *) pmask); } } return len - 1;
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